JPH09195833A - Apparatus for controlling accelerator of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system by which the cause of a trouble is cleared up quickly in the case an AI controlling apparatus system gets out of order and the system is smoothly repaired. SOLUTION: This apparatus is provided with a gear motor for governor operation, an acceleration lever 21, a sensor 26 for detecting the accelerator position, a sensor 34 for detecting the governor position, and a pressure switch for detecting whether a hydraulic actuator for an excavating work machine is driven or not. Moreover, being provided with a first accelerator controlling means A1 to achieve the rotation speed as the acceleration lever 21 sets and a second accelerator controlling means (AI control) A2 which achieves the rotation speed as the acceleration lever 21 sets at the time when a hydraulic actuator is driven and almost idles at the time when the hydraulic actuator is stopped, a circuit is so composed as to select the AI control state by a starting switch 51 and ring a buzzer 52 only when the hydraulic actuator is driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accelerator control device for a work machine such as a backhoe, a wheel loader, or a combine.

[0002]

2. Description of the Related Art In Japanese Patent Application No. 6-204072 filed earlier, the engine speed is controlled to a speed corresponding to the accelerator lever when the working device is in a driving state, and the accelerator lever is controlled when the working device is not driven. There has been proposed a so-called auto idle control device, which is a technique for improving the noise and the fuel consumption by controlling so as to automatically change to a substantially idling state regardless of the position.

[0003]

The automatic idle control (hereinafter abbreviated as AI control) is an electrically operated type in which an engine speed adjusting means is operated by an electric actuator, and a working device that controls the hydraulic pressure is a hydraulic device. It is driven. In this case, if a failure occurs in the AI control device, the self-diagnosis function is not provided at this stage, and it takes time to find out the cause of the failure and repair it, which is inefficient. . An object of the present invention is to provide a system capable of quickly investigating the cause of a failure in the AI control device and repairing it quickly.

[0004]

[Means for Solving the Problems]

[Arrangement] To achieve the above object, the present invention relates to an engine speed adjusting means, an electric actuator capable of driving and operating the engine rotating means, an accelerator operation tool manually operated, and an operation position of the accelerator operation tool. One sensor; and a second sensor for detecting the operating position of the engine speed adjusting means,
An operation sensor for detecting whether or not the hydraulic actuator for driving the work device is operating, and the first and second sensors are provided so that the engine speed corresponding to the operation position of the accelerator operation tool is expressed. A first accelerator control means that links the electric actuator is provided, and when the hydraulic actuator is operating, the engine speed corresponding to the operating position of the accelerator operating tool is displayed, and when the hydraulic actuator is stopped, the accelerator is operated. A second accelerator control means for automatically changing the engine speed to the idling side regardless of the operation position of the operation tool,
It is characterized in that an informing device is provided which is activated only when the operating state of the second accelerator control means is selected by the start switch and the hydraulic actuator is operating.

Further, it is convenient that the control valve of the hydraulic actuator is constructed as a pilot operated type and the operation sensor is constructed as a pressure switch for detecting an increase in pilot pressure for operating the control valve.

[Operation] According to the configuration of claim 1, as shown in FIG. 6, the start switch 51 and the operation sensors 25, 25
7 and 8 are connected in series and linked to the notification device 52, the truth table regarding the operation of the notification device 52 is as shown in FIG. That is, it is in the AI control state, and
The alarm device operates when the work device is moving, and does not operate when the work device is stopped even in the AI control state. Then, when not in the AI control state, the notification device does not operate regardless of whether the work device is driven or stopped.

Therefore, when the operation tool for work is operated in the AI control state (that is, the operation sensor is ON) and the work device does not move even though the alarm device is operating, the hydraulic system, not the electric system, fails. It can be determined that there is a high possibility. If the work device is moving but the alarm does not work, or if the drive speed of the work device is clearly slow (the electric actuator does not move), there is a high possibility that there is a failure in the electrical system. If it does not move and the alarm device does not operate, it means that there is a failure in either the electrical or hydraulic system. In the AI control state, and when the operation tool is not operated from the neutral position (that is, the operation sensor is OFF), the alarm system is activated or the engine speed is increased because of an electric system failure. There is a high possibility that the working device moves is likely to have a failure in the hydraulic system.

Further, in the non-AI control state and in the state where the operating tool is operated from the neutral position, the alarm device operates because of a failure of the electric system, and the working device does not move because of the hydraulic system. It can be judged as a failure. And non-AI
In the control state and in the state where the operation tool is not operated, it is highly likely that the alarm device operates and there is a failure in the electrical system, and the working device may operate in the hydraulic system. Can be judged to be high. In other words, although it is not possible to identify the failure point, it is possible to roughly judge whether the failure point is in the electric system or the hydraulic system, and the failure point can be narrowed down compared to the conventional method. It's fast and saves time in repairs.

According to the second aspect of the invention, if the hydraulic actuator for the working device is operating, the pilot pressure is increasing, and if it is not operating, the pilot pressure is decreasing. It can be determined whether or not it is operating by detecting it with a switch.

[Effect] As a result, in the accelerator control device according to any one of claims 1 and 2, the operation sensor and the start switch, which are originally provided, are connected in series and connected to the alarm device. By remodeling, it becomes possible to repair the AI control device when a failure occurs more quickly than before, and it is possible to more effectively use the AI control device that can maintain good work efficiency and improve fuel efficiency and noise. It became so.

In the accelerator control device according to the second aspect,
There is an advantage that the above effect can be achieved by a simple and economical means such as providing a pressure switch.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
A backhoe accelerator control device will be described with reference to the drawings. A backhoe is shown in FIG. 1, 1 is a crawler traveling device, 2 is a swivel base, 3 is an excavation work device, 19 is a dozer, and 20 is an operating unit. The excavation work device 3 is a swivel base 2.
A boom 4, an arm 5, and a bucket 6, which are mounted to be swingable up and down, and a boom cylinder 11,
The arm cylinder 12 and the bucket cylinder 13 are provided. The boom 4 has a parallel offset structure including an intermediate boom 14 and an offset cylinder 7. The driver's seat 30 is arranged in the driving unit 20,
The operation levers 9 and 10 capable of swinging the cross are arranged on both sides of the left and right sides.

FIG. 2 shows a hydraulic circuit. Briefly, among the control valves V1 to V9 of the center bypass type for the excavation work device 3, the crawler traveling device 1, etc.,
The arm cylinder 12, the boom cylinder 11, the bucket cylinder 13, and the four control valves V2, V5, V6, and V7 for the swing motor (not shown) are controlled by the pilot pressure by the pair of operating levers 9 and 10 described above. It is designed to be switched. Three hydraulic pumps 15, 16 and 17 driven by the engine 8 are for nine control valves, and 18 is a pilot valve 31 to switch the four control valves V2, V5, V6 and V7 described above. 34 is a pilot pump for supplying a pilot pressure to 34.

In this backhoe, the accelerator lever 21
The first and second sensors 26 and 43 and the geared motor 24 so that the engine speed corresponding to the operating position of
When the hydraulic actuator such as the boom cylinder 11 is operating, the engine speed corresponding to the operating position of the accelerator lever 21 is displayed and the hydraulic actuator is stopped. The second accelerator control means A2 for automatically changing the engine speed to the idling side regardless of the operation position of the accelerator lever 21 is provided.

That is, as shown in FIG.
Is equipped with a governor (an example of engine speed adjusting means) 22, a geared motor 24 for driving and operating a governor lever 23 thereof, a pressure switch (an example of an operation sensor) sensor 25 for detecting pilot pressure, and a hand accelerator lever 21. The control device 2 includes a first potentiometer 26 for detecting an operation position and a second potentiometer 43 for feedback for detecting a rotation operation amount of the geared motor 24.
The first and second accelerator control means A1 and A2 are connected to the control unit 7.

The first accelerator control means A1 is, in short,
This is a general electric operation control that uses the driving force of the geared motor 24 to express the engine speed as the operation of the accelerator lever 21, and the second accelerator control means A2 called so-called auto idle will be described below. Detailed description.

The second accelerator control means A2 operates the hand accelerator lever 21 at the idling position a,
The engine speed in the working state (usually set to the full accelerator position m) is set, the set speed is maintained in the working state, and the accelerator lever 21 is set to the position m in the non-working state (no load). The engine speed is reduced to almost idling while it remains set to.
Whether or not it is in a working state is determined by whether or not the pilot pressure is standing. That is, the control valve is switched to a position other than the neutral position when one of the operating levers 9 or 10 is operated to raise the pilot pressure, and when the pilot pressure is not raised, the control valve is in the neutral position. Is.

Therefore, it is judged whether or not it is in the working state based on the detection information of the two pressure switches 25, 25.
In the working state, the governor lever 23 is operated by the geared motor 24 so that the engine speed set by the hand accelerator lever 21 is obtained. In the non-working state, the geared motor 24 is driven to operate in the idling state. Is done. Also, the left and right traveling control valves V3, V
4 A travel detection switch (not shown) for detecting each neutral position is provided so that when both travel control valves V3 and V4 are neutrally operated, the idling state is automatically set.
Both traveling detection switches are connected to the control device 27.
Therefore, when the load is removed (travel stop) not only during work but also during traveling, the engine speed is automatically lowered from the set speed to idling.

Next, the accelerator operating device B for automatically operating the governor 22 will be described. As shown in FIGS. 3 to 5, an output arm 28 of a geared motor (an example of a drive operation actuator) 24 and a governor lever (an example of a lever to be operated) 23 are push-pull type operation wires (an example of an interlocking member) 29. Are linked together. Further, the governor lever 23 is urged back to the idling position i side by a return spring (not shown) installed in the governor 22. Then, the output arm 28 when the governor lever 23 is at the idling position so that the movement amount of the operation wire 29 per unit rotation angle of the output arm 28 becomes smaller as the rotation angle of the output arm 28 becomes larger.
The angle formed by the control wire 29 and the operating wire 29 is set smaller than the angle formed by the output arm 28 and the operating wire 29 when the governor lever 23 is at the maximum operating position.

That is, the included angle α between the output arm 28 and the operating wire 29 is about 75 degrees when the governor lever 23 is at the idling position i, and the governor lever 23
Is about 165 degrees when is at the maximum operation position max. The maximum rotation state is revealed by the contact between the pin 36 attached to the attachment substrate 35 of the geared motor 24 and the output arm 28, and the output arm 28 is surely rotated.
It is a structure to stop. A pin 36a may be provided to regulate the position of the output arm 28 even at the idling position.

In addition, the governor lever 23 and the operation wire 29
The included angle β between and is at the idling position i of the governor lever 23.
Is about 140 degrees and the governor lever 23
Is set to about 90 degrees when is at the maximum operation position max. That is, on the governor 22 side, the swing angle of the governor lever 23 with respect to the unit movement amount of the operation wire 29 becomes smaller as the non-operation swing angle of the governor lever 23 becomes larger, and the return biasing force is reduced. Governor lever 2 near the light idle position
3 moves greatly, but the movement is slowed near the maximum operation position. The governor lever 23 is configured to position the idling position i and the maximum operation position max by two stopper mechanisms 37 and 38.

Next, the current control of the accelerator operating device B will be described. In this accelerator operating device B, a position control means C for operating the governor lever 23 in accordance with the operation of the accelerator lever 21, a pressing control means D for making sure that the maximum engine speed is displayed, and a geared motor 24 at the operating position. A current gradual reduction control means E for surely stopping, a holding current control means (corresponding to a position holding control function) F for surely holding the governor lever 23 at the operation position,
The controller 27 is provided with a dead zone width adjusting control means G for automatically adjusting the dead zone width to prevent unnecessary hunting and a shutoff control means H for protecting the geared motor in the event of an abnormality such as a failure.

As shown in FIG. 6, a first potentiometer (an example of a first sensor) 26 for detecting the operating position of the accelerator lever 21 and a second potentiometer (an example of a second sensor) for detecting the operating position of the output arm 28. 43, a dead band width setting device 44, a geared motor 24, a power supply 45, etc. are connected to the control device 27. The second potentiometer 43 may be provided so as to directly detect the operation amount of the governor lever 23.

The position control means C is arranged so that the engine speed set by the accelerator lever 21 can be expressed.
The second potentiometer 26, 43 and the geared motor 24 are linked to drive the output arm 28. That is, when the accelerator lever 21 is rocked,
The operation amount is read by the first potentiometer 26, and the geared motor 24 is driven in the positive or negative direction so as to move the output arm 28 to a target operation position corresponding to the operation amount (hereinafter, defined as positive drive and negative drive). ) Do. And
Whether the output arm 28 has reached the target operation position is the second
When the potentiometer 44 reads and when different, the feedback control for driving the geared motor 24 positively or negatively is performed until the target operation position is revealed.

In the position control means C, as shown in FIG. 10, a motor for controlling the drive speed of the geared motor 24 according to the deviation value between the target stop position by the operation of the accelerator lever 21 and the current motor position. The speed control means Mc is provided in the control device 27. That is, if the deviation value is a value p1 or less which is small to some extent, the geared motor 2
4 is driven at the lowest speed, and a certain large value p2
Up to, the drive speed is increased or decreased according to the magnitude of the deviation value. When the deviation value exceeds the value p2, the geared motor 24 is driven at the maximum speed, which contributes to accurate and quick position control. Therefore, if the accelerator lever 21 is operated slowly, the geared motor 24 is driven at low speed, and if the accelerator lever 21 is operated quickly, the geared motor 24 is driven at high speed.

In the pressing control means D, the output arm 28 is
When the predetermined operation position s, which is set slightly before the maximum operation position max, is reached, the output arm 28 is forcibly operated to the maximum operation position max regardless of the detected value of the first potentiometer 26. That is, the torque is constantly generated by the geared motor 24 so that the output arm 28 is pressed to its operation limit.
3 and the geared motor 24 are linked.

That is, by reading the detected value k of the second potentiometer 43 in the position control state described above, it is possible to confirm that the operating position of the output arm 28 accompanying the swing operation of the accelerator lever 21 has reached the predetermined operating position s. If detected, as shown in FIG. 11, the geared motor 24
The drive current is rapidly increased to operate the governor lever 23 to the limit, and the output arm 28 is operated all at once to the maximum operation position max. Then, the current is gradually reduced to an idling current (holding current control state described later) required to generate a torque that can oppose the return biasing force of the governor lever 23, and that state is maintained. That is, the position control state and the pressing control state are switched at the predetermined operation position s. However, since the region up to the predetermined operation position s is in the position control state, the current at the pressing control start time is not necessarily constant, and as an example, as shown by the solid line, the one-dot broken line, the two-dot broken line, etc. in FIG.
It depends on the case by case.

When the output arm 28 reaches the target operation position by the position control means C, the current gradual reduction control means E causes the drive current of the geared motor 24 to oppose the return urging force of the governor lever 23 at the operated position. The control is performed to gradually reduce the idling current required to generate. That is, when the current to the geared motor 24 is suddenly cut off, the return biasing force acts on the geared motor 24, which is in a dynamic friction state, and it is easy to be pushed back from the target operating position. In this case, the return biasing force acts on the geared motor 24 in the static friction state, and it is possible to sufficiently oppose the biasing force and prevent the push-back from the target operation position.

That is, as shown in FIG. 12, when the dead zone (described later) of the target stop position (target operation position) is reached by the positive drive in the direction of increasing the engine speed, the positive drive at that time is reached. The current is linearly reduced to the holding current (idling current) (solid line). If the dead zone is reached by negative drive, which is the direction of decreasing the engine speed, the negative drive current at that point is used as the raw value. The holding current is gradually changed (dashed line). Further, in a geared motor with an external speed reduction mechanism (with spring assist) (not shown), a negative holding current is settled near the idling position (two-dot broken line). As a mode of gradually decreasing (or gradually increasing) the current, a method of gradually decreasing the current value (ampere) (linearly or non-linearly) or a method of changing the duty ratio of the pulse current may be used. In short, the idling current is not reduced suddenly, but is gradually reduced. Note that, in FIG. 12, the parallel portions of the solid line and the dashed-dotted line have the same current value.

The holding current control means F supplies a holding current (idling current) required for the geared motor 24 to generate a torque that can oppose the return biasing force of the governor lever 23 after the output arm 28 reaches the target operating position. As described above, it operates after the pressing control means D or the current gradual reduction control means E. The geared motor 24 can be manually operated in case of failure,
It incorporates a reduction mechanism (not shown) that uses a spur gear instead of a worm gear. Therefore, the total resistance of the frictional resistance of the spur gear reduction mechanism, the sliding resistance of the operation wire 29, and the brush resistance of the motor is not sufficient to stop the output arm 28 in opposition to the return biasing force. By generating an unsatisfactory amount of torque by the motor, the torque is reliably held at the target operation position.

That is, the map data of the holding current corresponding to the angle of the output arm 28 (that is, the angle of the governor lever 23) is stored in the control device 27 in advance, and the map data is held after the output arm 28 reaches the target operating position. The holding current is controlled so as to be maintained. Specifically, as shown in FIG. 13B, in the case of the geared motor 24 of the type in which no assist spring is attached to the output arm 28, in the front half angle range of the entire rotation angle of the output arm 28,
Since the holding resistance current is zero because the return resistance of the governor lever 23 can be counteracted by the total resistance described above, the holding current map data that the holding current is linearly increased in the turning angle region of the latter half of that is the control device. It is input to 27.

On the other hand, as shown in FIG. 13 (a), in the case of a geared motor with an external reduction gear (not shown) in which an assist spring for urging the output arm 28 in the direction of increasing the engine speed is mounted, By canceling the return urging force of the governor lever 23 and the urging force of the assist spring 42, the output arm 2
A negative holding current is supplied in the front quadrant of all the rotation angles of 8, and a positive holding current is supplied in the rear quadrant, and
The holding current is set to zero in the quadrant of the two central portions.

The dead zone width adjusting control means G controls to automatically expand the dead zone when the number of times of quick hunting of the geared motor 24 in the position control is larger than a predetermined number, and prevents unnecessary hunting. Thus, the output arm 28 is stopped and held at the target operation position. That is, in the position control means C, the operating position of the output arm 28 corresponding to the operating position of the accelerator lever 21 is set to one point in order to allow a slight overrun after the de-energization of the geared motor 24 or to avoid continuous hunting. Rather, it is defined as an operation area with a certain width. When the operation area corresponds to the dead zone and the output arm 28 is located at a portion where the dead zone corresponding to the operation position of the accelerator lever 21 overlaps, the output arm 28 does not move even if the accelerator lever 21 is finely operated. It works like this.

The control operation when hunting occurs will now be described with reference to FIGS. 14 and 15. Here, it is assumed that the dead band width is expanded if quick hunting occurs twice. First, the dead band width is set by operating the setting device 44 before starting the control, and then the accelerator lever 2
1 is operated by an appropriate amount in the direction of increasing the engine speed in the range from the idling position a to the predetermined operation position s or less. Then, when the position control means C reaches the minimum operation position in the dead zone of the target stop position [FIG. 14 (a)], the supply current is gradually reduced to the idling current by the gradual reduction control. That is, if the detected value k of the second potentiometer 43 passes through the maximum target operating position in the dead zone and then escapes to the opposite side, hunting will occur.

In this case, if the time required for the exit is within a predetermined time (previously stored in the control device 27), the number of times of hunting is counted and the position is controlled again (FIG. 14B). (However, if it is longer than the predetermined time, it is not counted and returns to the position control state). Then, when the geared motor 24 is negatively driven by the position control and the detected value k of the second potentiometer 43 reaches the maximum operating position in the dead zone [Fig. 14 (c)], the idling current required at that position is gradually increased by the gradually decreasing control. Although the supply current is reduced, if the detected value k stops within the dead zone even during that period, the control switches to holding current control and the control ends (Fig. 14 (d)), but the minimum operation position in the dead zone is exceeded. If this is the second hunting.

In that case, if the time required for exiting the dead zone is longer than the above-mentioned predetermined time, the hunting count is not returned and the position is returned to the position control state (FIG. 15 [e]), and the detected value is obtained by the positive drive of the geared motor 24. If k stops within the dead zone, the control is switched to the holding current control and the control ends [Fig.
(F)) However, if the dead zone exit time is again within the predetermined time (FIG. 15 [TO]), the hunting count is performed twice, the dead zone width is expanded (FIG. 15 [CH]), and the control returns to the position control. That is, the control operation is repeated until the detected value k falls within the dead zone by hunting a predetermined number of times or less.

That is, depending on the state of hunting, FIG.
4, each action of (a) to (h) shown in FIG.
(B) → (B) → (C) → (D), (B) → (B) →
(C) → (e) → (f), and (a) → (b) →
There are various combinations that operate in the order of (C) → (G) → (H), and the point is that the dead band width is widened when the frequency of hunting is higher than the set state.

In a series of operations, it is judged whether or not the hunting is such that the dead zone is passed within a predetermined time.
In addition, the frequency detection means 48 for detecting the hunting frequency by counting the rapid hunting frequency is configured. Then, when the number of quick hunting times exceeds a predetermined number, the dead band width is expanded as compared with the initially set state, and the dead band width is automatically adjusted until unnecessary hunting does not occur. This adjustment of the dead band width is electrically processed to display the setting section 44 (liquid crystal display, etc.) 4
It is convenient to display in 4a together with the initial set value, because it is possible to grasp the change state of the dead zone by the dead zone width adjustment control means G.

The cutoff control means H comprises an ammeter 46 for detecting the current value to the geared motor 24 and a measuring means 47 for detecting the time required for the second potentiometer 43 to reach the target value. When the detection time by the measuring means 47 is longer than the predetermined time, the geared motor 24 is operated so as to be de-energized. The predetermined time is the time required to move the maximum operation amount of the geared motor 24, and specifically, the gear time required to operate the output arm 28 from the idling position i to the maximum operation position max (or vice versa). It is set in the control device 27 as a continuous drive operation time of the motor 24 or a time obtained by adding a slight error time thereto.

That is, when the operation wire 29 rusts and the frictional resistance increases, the following speed of the output arm 28 is slow, or when foreign matter is caught, it becomes impossible to swing and the geared motor 24 cannot be swung. Since the current increases more than usual, the cut-off control means H acts so as to judge that the control is abnormal and cut off the power supply to the geared motor 24.

The series of controls described above is performed according to the flow chart shown in FIG. First, the dead band width is set by the setter 44 (# 1), and then the accelerator lever 21 at the idling position is operated to a predetermined operating position (# 2) so that the engine 8 is rotated. To raise. Then, the detected value k of the second potentiometer 43 by the position control (# 3) is a predetermined value (s of the output arm 28
Position), the control is switched from the position control to the pressing control (# 5), the output arm 28 is pressed toward the maximum operating position max so that the engine speed becomes maximum, and then the holding current control state (# 6). )become.

If the detected value k of the second potentiometer 43 is smaller than the predetermined value, the time required to reach the dead zone of the target value is detected (# 7), and if the time is longer than the predetermined time. The cutoff control means H (# 8) which cuts off the power supply to the geared motor 24 is activated due to some abnormality,
The control is interrupted. If the arrival time is within the predetermined time and is within the dead zone (# 10), the current gradual reduction control means E (# 9) is activated to fade out the supply current to the geared motor 24 and stop it. The control is switched to the holding current control of 6, and the output arm 28 is held at that position. At that time, and if the detection value k of the second potentiometer 43 is outside the set dead zone in # 10 and the time required to pass through the dead zone is longer than the predetermined time (# 11), # 3 is again set. Returning to the position control, the geared motor 24 is restarted from the state of being negatively driven. In other words, if the dead zone exit time is long,
Since this state is not repeated thereafter, the idea is not to target the dead zone.

If the dead zone passing time is shorter than the predetermined time, there is a high possibility that hunting will be repeated thereafter. Therefore, the dead zone is considered to be expanded and the frequency detecting means 48 functions to count the number of hunting times (# 1).
2). If the number of times of hunting is 1 time or less, the position control of # 3 is repeated, and if the number of times of hunting is 2 times, the dead zone width is expanded (# 1
3) Then, start again from the position control of # 3.
That is, when the hunting is performed twice or more, it is determined that the dead zone is narrow, and the dead zone width adjusting control unit G operates to expand the dead zone. If the dead zone initially set is very narrow, the dead zone enlargement adjustment is 2 It may occur more than once. The detailed control operation status associated with this hunting is
This has already been described with reference to FIGS. The above current control operation is similarly exerted during the automatic adjustment operation of the geared motor 24 by the automatic acceleration device A.

As shown in FIG. 6, the start detecting means I for detecting whether or not the engine 8 has been started, and the fact that the engine speed corresponding to the operating position of the governor 22 or corresponding to the engine speed has appeared. And a rotation detecting means 50 for detecting,
After the engine is started, the control by the first accelerator control means A1 is executed until the rotation detecting means 50 is detected, and after the rotation detecting means 50 is detected, the control by the second accelerator control means A2 is executed. As described above, the switching control means J that links the activation detection means I and the first and second accelerator control means A1 and A2 is provided.

Next, a plurality of relational data with respect to the actual engine speed when the governor lever 23 is operated by a predetermined amount are obtained, and from the obtained plurality of relational data, the rotational speed adjustment positional relation (engine with respect to the operation amount of the governor 22 is calculated. The method of setting the relationship of the number of revolutions) will be described. Governor lever 2
Since the operation amount of No. 3 is replaced with the second potentiometer 43 provided in the geared motor 24 portion, actually, the adjustment operation for setting the relationship between the drive amount of the geared motor 24 and the engine speed is performed. is there.

The predetermined drive amount of the geared motor 24 is
Governor lever 2 so that the maximum engine speed is revealed
When 3 is operated to the limit position on the full accelerator side, the economy rotation speed that is the minimum rotation speed that can maintain the load sensing system appears, and the idling side specified by the action of the auto idle control. 4 when the AI (abbreviation of auto idle) rotation speed, which is the rotation speed, appears and when the idling rotation speed appears.
Ask about points. Then, as shown in the graph of FIG. 17, by plotting the above-mentioned four points and connecting two adjacent points with a straight line, the drive amount of the geared motor 24 and the engine speed are calculated from the relational data of the four points obtained. , That is, the rotational speed adjustment positional relationship is set.

The flowchart of FIG. 18 shows the procedure of the adjusting operation, and the adjusting operation mode is selected in advance by turning on the adjusting switch (not shown). First, the pressing control means D is made to function to learn the drive amount of the geared motor when the governor lever 23 is operated to the maximum limit position (# 1). Next, the geared motor 24 is slowly driven in the direction of decreasing the engine speed, and PI (proportional + integral) control is performed toward the target learning speed (# 2).

Then, the rotational speed measured by the tachometer 50 falls within ± α (for example, 3%) of the target learning rotational speed, and
It is judged whether or not 3 seconds or more have passed for stabilizing the rotation speed (# 3), and if the condition is satisfied, the drive amount of the geared motor 24 at that time is stored (# 4). Return to # 2. Then, when step # 4 has passed, the presence or absence of the next target learning value is checked (# 5), and if it exists, the process returns to step # 2, and if not, the control of the adjusting operation ends.

FIG. 17 obtained by the above adjusting operation
Line c is a polygonal line relationship that is close to the true line b, and line d is approximately 80 to 95% of the line c.
It is a relationship showing the rotation speed of the medium value. Line c is the maximum speed, economy speed (2100 rpm), AI
(Short for auto idle) Idling speed (1400
rpm) and the idling speed (1150 rpm) at four points, the operation amount of the geared motor is measured by an actual machine, and the line is obtained by connecting the four points. Therefore, in this case, step # 5 in the flowchart shown in the figure is repeated twice. Further, the line d is a predetermined rotation speed for the line c which is regarded as the engine rotation speed corresponding to the accelerator lever 21. Incidentally, the load sensing for maintaining the differential pressure between the load of the working device and the pump pressure at a predetermined value is a known technique in Japanese Patent Application Laid-Open No. 7-103204, and the details thereof will be omitted here.

Line d serves the following functions: That is, when the engine 8 is started with the accelerator lever 21 set to a certain operating position, the cold engine rotates at a rotational speed considerably lower than the original rotational speed.
The rotational speed increases as the air is warmed and warms up, and when the warm-up operation ends, the rotational speed reaches the line c. Therefore, the lines c and d are stored in the control device 27 upon completion of the adjustment operation described above, and the measured value (rotation speed) of the tachometer (pickup or the like) 50 after the engine is started is indicated by the line d. When it exceeds, it is considered that the warm-up operation is almost completed, and the switching control means J functions so as to switch from the first accelerator control means A1 state up to the second accelerator control means A2 state, that is, the auto idle state. . In this case, since there is a possibility of restarting due to engine stall, it is determined that the engine 8 has been started by maintaining the measurement value of the tachometer 50 at 600 rpm or more. It is configured for dual use.

FIG. 16 is a flow chart showing the operation of the switching control means J. First, the tachometer 50 judges whether or not the engine has been started (# 1). . It is judged whether 4 seconds have passed (# 2), and if it has passed, it is judged whether the measured value by the tachometer 50 has reached the line d shown in FIG. 17 (# 3). For example, it is considered that the warm-up operation has ended and the automatic idle control state is switched to (# 4). Actually, the second accelerator control means A2 is passed 4 seconds after the switching.
It is controlled so as to reduce the AI idling rotation speed (1400 rpm).

As shown in FIG. 6, the activation switch 51 selects the operating state of the second accelerator control means A2,
In addition, a buzzer (an example of a notification device) 52 that operates only when a hydraulic actuator such as the boom cylinder 11 is operating is provided. That is, two pressure switches 25, 25 and a start switch 51 connected in series,
And a buzzer 52 are connected to the control device 27 so that the two pressure switches 25, 25 both operate and the second
Buzzer 5 only when accelerator control means A2 is selected
2 is supposed to ring.

Therefore, the truth table (combination table) of the buzzer 52 not ringing is as shown in FIG. That is, A
The buzzer 52 sounds when the pilot pressure is in the I control state and rises, and the buzzer 52 does not sound when the pilot pressure does not rise even in the AI control state. And non-AI
In the control state, the buzzer 52 does not sound regardless of whether the pilot pressure is standing. Therefore, when the start switch 51 is turned on and the operating lever 9 or 10 is tilted from the neutral position, the buzzer 52 sounds, and when it is returned to the neutral position, the buzzer 52 stops. The notification device 52 may be a lamp or a single pressure switch 25. Further, the starting switch 51 may be configured as a switch for selectively selecting either one of the first and second accelerator control means A1 and A2.

FIG. 8 shows a flowchart of the self-diagnosis function relating to the control device 27 and the like. In other words, if it is conventional, even if it is known whether a failure has occurred,
I didn't know until that time, and I couldn't determine whether it was a fundamental failure or a failure that caused symptoms when the temperature increased. Therefore, in the device of the present application, the microcomputer keeps measuring the time from turning on the key (main switch), and the time (t) when the failure occurs can be stored. In other words, even if you do not know the absolute time, you can judge whether it is a failure immediately after the key is turned on or a failure after many minutes, and it is very useful for diagnosing failures without reproducibility. I try to help.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a side view of a backhoe.

FIG. 2 is a hydraulic circuit diagram

FIG. 3 is a plan view showing an arrangement state of an accelerator operating device in a real machine.

FIG. 4 is an operation diagram showing an idling state of the accelerator operating device.

FIG. 5 is an operation diagram showing a maximum operating state of the accelerator operating device.

FIG. 6 is a block diagram showing a control system of an accelerator operating device and its current control device.

FIG. 7 is a diagram showing a truth table regarding the operation of the buzzer.

FIG. 8 is a diagram showing a flowchart of a self-diagnosis function.

FIG. 9 is a diagram showing a flowchart of current control.

FIG. 10 is a diagram showing an operation target speed graph of a geared motor.

FIG. 11 is a diagram showing a change over time in current due to pressing control.

FIG. 12 is a diagram showing a change over time in current due to current gradual decrease control.

FIG. 13 is a diagram showing a change with time of current in holding current control.

FIG. 14 is a conceptual diagram 1 showing the functions of hunting and dead zone width adjustment control.

FIG. 15 is a conceptual diagram showing the functions of hunting and dead zone width adjustment control.

FIG. 16 is a diagram showing a flowchart of a switching control means.

FIG. 17 is a diagram showing a graph of a rotational speed adjustment positional relationship.

FIG. 18 is a view showing a flowchart for obtaining data on the rotational speed adjustment positional relationship.

[Explanation of symbols]

 11 Hydraulic Actuator 21 Accelerator Operation Tool 22 Engine Rotation Speed Adjusting Means 24 Electric Actuator 25 Actuation Sensor 26 First Sensor 43 Second Sensor 51 Start Switch 52 Notification Device A1 First Accelerator Control Means A2 Second Accelerator Control Means V5 Control Valve

Claims (2)

[Claims] 1. An engine speed adjusting means (22), an electric actuator (24) capable of driving and operating the same, an accelerator operating tool (21) manually operated, and an operating position of the accelerator operating tool (21). The first sensor (2
6), a second sensor (43) for detecting the operating position of the engine speed adjusting means (22), and an operation sensor (for detecting whether or not the hydraulic actuator (11) for driving the working device is operating. 25), the first and second sensors (26) and (43) and the electric actuator (24) so that the engine speed corresponding to the operation position of the accelerator operation tool (21) is expressed. )
And a first accelerator control means (A1) for linking with each other, and when the hydraulic actuator (11) is operating, the engine speed corresponding to the operating position of the accelerator operating tool (21) is displayed, Hydraulic actuator (1
When 1) is stopped, the accelerator operation tool (2
The second accelerator control means (A2) for automatically changing the engine speed to the idling side regardless of the operation position of 1) is provided, and the start switch (51) is used to activate the second accelerator control means (A2). An accelerator control device for a working machine, comprising an informing device (52) which is activated only when an operating state is selected and the hydraulic actuator (11) is operating. 2. A pressure for detecting an increase in pilot pressure for operating the control valve (V5), wherein the control valve (V5) of the hydraulic actuator (11) is of a pilot operated type, and the operation sensor (25) is for detecting an increase in pilot pressure for operating the control valve (V5). The accelerator control device for a working machine according to claim 1, wherein the accelerator control device comprises a switch.